Keys Are Integers Whenever Possible¶

<?php

$array = [];
$array["01000"] = "Bourg-en-Bresse";
$array["75001"] = "Paris";

var_dump($array);

Array keys are only strings or integers: the later has priority. So, when storing a string that can be converted to an integer, PHP does the conversion automatically.

In the case displayed, the keys are French zip codes, which might start with a leading 0. But PHP converts it into integer, and drops that leading 0. The value is still correctly indexed, but now, the string representation has changed.

See Also¶

Array: syntax (PHP manual)
integer or string? [Try me]

PHP Features¶

Last updated: 14 July 2026